Rotameter



Feb. 4, 1941. A. K. FISCHER OATAMETE'R Filed May 27, 1938 I?atented Feb. ,"4, i941 armo sTATEs andere rmEN'rN Fries nomineren Application M ay 27, 1938, Serial No. 210,417

ll (Claim. The principal object of the present invention is to protect the tapered glass tubes oi' rotameters against accidental breakage from the outside and also to reduce the accident hazard in case the tapered glass tubes burst.

Another object of the invention is to provide comparatively simple and inexpensive means for equipping rotameters with such protection.

` It may be remarked that the tapered tubes i@ are important parts of an instrument pf precision and therefore their'form is of the utmost importance. Experience has proven that glass is practically the only material with which the required precision of form can be obtained but B glass while suiilciently transparent is relatively iriable and easily broken when tubes are struck from `the outside and, therefore, its strength is limited so that when these glass tubes burst from internal pressure they create an accident hazard. 20 Of course there are materials which are transparent and suiiicientiy strong to resist accidental blows and internal pressure but they do not lend themselves to the production of tapering tubes oi the necessary precision and accuracy of form. 2li The present invention comprises a rotameter tube of transparent material adapted for production in the 'required tapering form but relatively iriable and a cylindrical tube enclosing the tapering tube and oi transparent material t@ adapted for production in cylindrical form but not in the required tapering form and relatively non-friable.

The invention als comprises the improve- 'ments to be presently described and ilnally 36 claimed. n 4

In the following description reference will be made to the accompanying drawing forming part hereof and in which,

Figure 1 is a vertical sectional view of a rotem- 40 eter embodying features of the invention, and

Figure 2 is a sectional viewtaken on the line 2-2 of Fig. 1 and drawn to an enlarged scale.

Referring to the drawing l is a tapering tube of glass or other transparent'material adapted 45 `for production in tapering form but necessarily relatively friable. This tube l is arranged in the path of the liquid or uid to be measured and is mounted in stufling boxes 2 having glands l. B is Ai cylindrical tube enclosing the tapering tube 50 l and it is of transparent material adapted for production in cylindrical form but not in tapering form and the material is relatively non-friable. The cylindrical tube l may be made of synthetic material such as Luclte supplied by the Du Pont Company; Celluloid made by the Celluloid Company; and Plexiglas made by Rohm & Haas Company in Philadelphia. This cylindrical tube Cl surrounds the taper tube l and is mounted at its ends in anges 5 provided on the glands 3. 5 By the described conjoint use of two materials of which one is susceptible of production with the required degree of accuracy and in the required tapering form and of which the other is incapable of production in the required tapering form but may be readily produced in cylindrical form and by the discovery that while one of them is lacking in strength the other of them is sufficiently strong, there is produced a transparent tube structure for rotameters which perl5 mits them to perform their required precision of measurement and at the same time protects those employed in and around them from accidental injury in the event of the bursting of the ytapering tube.

it may be remarked that the tube t is spaced from the tube l and is supported by the non- -breakable frame of the instrument, so that if the non-breakable metal frame of the instrument receives a shock from the outside the shock is resisted bythe comparatively non-friable tube 4. Similarly a blow on the tube d is resisted by it and the glass tube l is not broken. The tube t is placed in position by rst inserting into -it the tube l then the stuffing boxes 2 are applied to the ends of the tube l and the flanges Elon the glands 3 are placed on the ends of the tube t; then the assemblage is inserted sidewise between the columnsshown as crosshatched in Figure 2 and mounted in proper posi- 35 tion; then the bolts whose heads are shown in Figure 2 are tightened in respect to the end littings. The tube is shown as somewhat shorter than the vertical distance between the upper flange 5 and the bottom of the lower flange 5. 40

yThe tube t is not held in position in vertical direction but is held by the flanges 5 insidewise direction. This is descriptive of the structure shown in the drawing for thesake of illustration.,

It will be obvious to those skilled in the art to which theinvention relates that modiiications may be made in details of construction and arrangement without departing from the spirit of the invention which is not limited otherwise than as the appended claim may require.

I claim:

In a rotameter for measuring the ilow of a fluid the combination of a tapering tube of transparent but relatively friable material, a cylinanges which support the cylindrical tube in position surrounding the tapering tube at an even distance from the tapering, friable tube without touching same thereby resisting any shocks from the outside With the non-breakable frame of the rotameter.

ADELBERT K. FISCHER. 

